[Xorg] Damage/Composite + direct rendering clients

[Andy Ritger]

On Tue, 18 May 2004, Keith Packard wrote:

> 
> Around 1 o'clock on May 18, Andy Ritger wrote:
> 
> > I'm debating whether it is better for the X server to not even know
> > of the damage until it has completed in hardware, or if it is
> > better to tell the X server as soon as the rendering has kicked off,
> > and then require X to wait for completion only when it needs to
> > use the drawable as a source.
> 
> I don't think we'll be able to know which is best without giving them both 
> a try.  I was quite surprised at what method turned out best for the 
> compositing manager -- one has been taught to avoid round trips at all 
> cost, but the lowest latency was accomplished with an XSync call in the 
> middle of the drawing loop.
> 
> Just goes to show that intuition and reality are often in conflict...

Yup; this will require some experimentation to get right, but
atleast there are several options.

Thanks,
- Andy